import numpy as np
import time

start_time = time.perf_counter()

n = 4000000
x = np.linspace(0,100,n)
y = np.linspace(20, 300, n)
dot = np.dot(x, y)
stop_time = time.perf_counter()
cost_time = stop_time - start_time

print(f"The dot product is {dot} computed by numpy and {cost_time:.8f} costed.")